People for whom Verilog is bread and butter
Here are some of the Verilog vendors. This
list, by no means, is exhaustive and purely based on their popularity rather
than their usefulness or efficiency.
Mentor Graphics: Mentor Graphics
ModelSim came from Model Technology. ModelSim is a popular simulator for
some users, particularly those who use PCs for simulation.
Design Systems : Verilog-XL, the first Verilog Simulator, retained
its popularity for many years. Cadence has stopped adding new features to XL
for a long time now, but somehow many people still like it. Cadence also has
NC Verilog, which is a compiled Verilog simulator. Verilog-XL and
NC-Verilog were the first commercial simulators to support both PLI1.0
and PLI2.0 of IEEE Std.1364-1995 Verilog.
(now part of Synopsys ) came up with the first compiled
(i.e. not interpreted) version of Verilog, called VCS and it turned out
to be 3-4 times faster than Verilog-XL. Since then their race against time
is on and God knows where they will end up. VCS does not support PLI2.0 yet,
and more than that it is still unknown whether they will ever
came up with yet another kind of Simulator (apart from interpretive
event-driven and compiled event-driven), known as cycle based simulators.
This class, by their very nature, is very fast (around 10 times than others),
but the catch is that the simulation is done only at certain edges of specified
set of signals.
Design Accelaration Inc's
Signalscan is a complete platform for debugging and signal viewing. Ideawise
it is pretty cool. Their waveform viewer is one of the bests in the industry,
but one wishes that one could say the same about their debugging utilities.
Veritools Inc came up
with one of the first waveform tools in the industry - Undertow.
Accellera is a
non-profit organization, which is dedicated for HDL related development.
You can purchase their version of Verilog Language Reference Manual (now in its
second version) and PLI reference manuals. Accellera is also the organizing
body for SystemVerilog 3.0, 3.1, 3.1A and 3.1AE development. The LRMs for
SystemVerilog can be obtained from here.
IEEE is another not for profit
organization (press your browser's back button several times, if you have not
heard of them). IEEE's standard committee has published IEEE Std.1364-1995
Verilog manual. You can buy it directly online.